Sick sinus syndrome

This is where the heart's natural pacemaker, the sinoatrial node, becomes damaged and the heart beats too slowly or misses a few beats.

Most cases are caused by ageing. It can be a result of coronary artery disease and disease of the heart muscle (cardiomyopathy).

With sick sinus syndrome, the following symptoms come and go suddenly.

• Palpitations
• Brief attacks of light-headedness
• Breathlessness
• Loss of consciousness (syncope)

Sick sinus syndrome is usually diagnosed by carrying out an ECG (electrocardiogram). As the symptoms can come on at any time, the doctor may want to monitor your heart over 24 hours. The treatment for sick sinus syndrome is having a pacemaker fitted.